On the bonding of Ga2, structures of Gan clusters and the relation to the bulk structure of gallium

Gallium is an unusual metal, sometimes described as a molecular metal, composed of covalently bonded-dimers, with metallic bonding primarily in the plane perpendicular to the average alignment of the dimers. We analyse the interactions between Ga2 molecules, and compare the calculated structures of small clusters to the complicated structure of the bulk. Both density functional and wavefunction-based methods are employed. The structures of small neutral clusters are shown to be remarkably similar to certain features of the bulk (α-Ga) structure. DFT calculations perform well in comparison to coupled cluster calculations in the size range considered.